title: Optimal left ventricular lead position predicts reverse remodeling and survival after cardiac resynchronization therapy.
abstract: OBJECTIVE
  The aim of the current study was to evaluate echocardiographic parameters after 6 months of cardiac resynchronization therapy (CRT) as well as long-term outcome in patients with the left ventricular (LV) lead positioned at the site of latest activation (concordant LV lead position) as compared with that seen in patients with a discordant LV lead position.
  
  
  BACKGROUND
  A nonoptimal LV pacing lead position may be a potential cause for nonresponse to CRT.
  
  
  METHODS
  The site of latest mechanical activation was determined by speckle tracking radial strain analysis and related to the LV lead position on chest X-ray in 244 CRT candidates. Echocardiographic evaluation was performed after 6 months. Long-term follow-up included all-cause mortality and hospitalizations for heart failure.
  
  
  RESULTS
  Significant LV reverse remodeling (reduction in LV end-systolic volume from 189 +/- 83 ml to 134 +/- 71 ml, p < 0.001) was noted in the group of patients with a concordant LV lead position (n = 153, 63%), whereas patients with a discordant lead position showed no significant improvements. In addition, during long-term follow-up (32 +/- 16 months), less events (combined for heart failure hospitalizations and death) were reported in patients with a concordant LV lead position. Moreover, a concordant LV lead position appeared to be an independent predictor of hospitalization-free survival after long-term CRT (hazard ratio: 0.22, p = 0.004).
  
  
  CONCLUSIONS
  Pacing at the site of latest mechanical activation, as determined by speckle tracking radial strain analysis, resulted in superior echocardiographic response after 6 months of CRT and better prognosis during long-term follow-up.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ypenburg
authors.forename: Rutger J
authors.initials: RJ
authors.lastname: van Bommel
authors.forename: Victoria
authors.initials: V
authors.lastname: Delgado
authors.forename: Sjoerd A
authors.initials: SA
authors.lastname: Mollema
authors.forename: Gabe B
authors.initials: GB
authors.lastname: Bleeker
authors.forename: Eric
authors.initials: E
authors.lastname: Boersma
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods; D015150:Echocardiography, Doppler; D004567:Electrodes, Implanted; D005260:Female; D005544:Forecasting; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012720:Severity of Illness Index; D013318:Stroke Volume; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D020257:Ventricular Remodeling